Search Results (1,279)

Background/Objectives: This study aimed to examine the changes in brain metabolites and water molecule diffusion using chemical exchange saturation transfer (CEST) imaging and diffusion-weighted imaging (DWI) after 15 Gy of X-ray irradiation in a rat model of glioma. Methods: The glioma-derived cell line, C6, was implanted into the striatum of the right brain of 7-week-old male Wistar rats. CEST imaging and DWI were performed on days 8, 10, and 17 after implantation using a 7T-magnetic resonance imaging. X-ray irradiation (15 Gy) was performed on day 9. Magnetization transfer ratio (MTR) and apparent diffusion coefficient (ADC) values were calculated for CEST and DWI, respectively. Results: On day 17, the MTR values at 1.2 ppm, 1.5 ppm, 1.8 ppm, 2.1 ppm, and 2.4 ppm in the irradiated group decreased significantly compared with those of the control group. The standard deviation for the ADC values on a pixel-by-pixel basis increased from day 8 to day 17 (0.6 ± 0.06 → 0.8 ± 0.17 (×10⁻³ mm²/s)) in the control group, whereas it remained nearly unchanged (0.6 ± 0.06 → 0.8 ± 0.11 (×10⁻³ mm²/s)) in the irradiated group. Conclusions: This study revealed the effects of 15 Gy X-ray irradiation in a rat model of glioma using CEST imaging and DWI. Full article

Background: Secondary (nosocomial) bacterial meningitis remains a serious problem in patients with severe brain damage. The aim of this study was to assess the differences in the aromatic metabolites of tryptophan, phenylalanine, and tyrosine, in serum and cerebrospinal fluid (CSF) samples collected simultaneously from patients with long-term sequelae of severe brain damage with suspected secondary bacterial meningitis. Methods: Group I included 16 paired serum and CSF samples from patients (N = 11) without secondary bacterial meningitis; group II included 13 paired serum and CSF samples from patients (N = 4) with secondary bacterial meningitis. Results: The median concentrations of serum 5-hydroxyindole-3-acetic, CSF 4-hydroxyphenyllactic (p-HPhLA), CSF 4-hydroxyphenylacetic, CSF phenyllactic, and indole-3-lactic acids in serum and CSF were statistically higher in group II compared to group I (p-value ≤ 0.03), while 4-hydroxyphenylpropionic and indole-3-acetic in serum were lower in group II compared to group I (p-value = 0.04). In group I, p-HPhLA serum concentrations were greater than or equal to its CSF concentrations in 14 paired samples; in group II, p-HPhLA concentrations in serum were lower than in CSF in all paired samples. Conclusions: The obtained results demonstrate the differences in the profile of aromatic metabolites in serum and CSF and may confirm the hypothesis of the p-HPhLA microbial origin in the CSF of patients with secondary bacterial meningitis. Full article

Background/Objectives: Selective serotonin reuptake inhibitors (SSRIs), widely prescribed for anxiety disorders, may negatively impact the gut microbiota, contributing to dysbiosis. Considering the gut–brain axis’s importance in mental health, probiotics could represent an effective adjunctive strategy. This study evaluated the effects of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 on microbiota composition, metabolic activity, and immune markers in fecal samples from patients with anxiety on SSRIs, using the SHIME^® (Simulator of the Human Intestinal Microbial Ecosystem) model. Methods: The fecal microbiotas of four patients using sertraline or escitalopram were inoculated in SHIME^® reactors simulating the ascending colon. After stabilization, a 14-day probiotic intervention was performed. Microbial composition was assessed by 16S rRNA sequencing. Short-chain fatty acids (SCFAs), ammonia, and GABA were measured, along with the prebiotic index (PI). Intestinal barrier integrity was evaluated via transepithelial electrical resistance (TEER), and cytokine levels (IL-6, IL-8, IL-10, TNF-α) were analyzed using a Caco-2/THP-1 co-culture system. The statistical design employed in this study for the analysis of prebiotic index, metabolites, intestinal barrier integrity and cytokines levels was a repeated measures ANOVA, complemented by post hoc Tukey’s tests to assess differences across treatment groups. For the 16S rRNA sequencing data, alpha diversity was assessed using multiple metrics, including the Shannon, Simpson, and Fisher indices to evaluate species diversity, and the Chao1 and ACE indices to estimate species richness. Beta diversity, which measures microbiota similarity across groups, was analyzed using weighted and unweighted UniFrac distances. To assess significant differences in beta diversity between groups, a permutational multivariate analysis of variance (PERMANOVA) was performed using the Adonis test. Results: Probiotic supplementation increased Bifidobacterium and Lactobacillus, and decreased Klebsiella and Bacteroides. Beta diversity was significantly altered, while alpha diversity remained unchanged. SCFA levels increased after 7 days. Ammonia levels dropped, and PI values rose. TEER values indicated enhanced barrier integrity. IL-8 and TNF-α decreased, while IL-6 increased. GABA levels remained unchanged. Conclusions: The probiotic combination of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 modulated gut microbiota composition, metabolic activity, and inflammatory responses in samples from individuals with anxiety on SSRIs, supporting its potential as an adjunctive strategy to mitigate antidepressant-associated dysbiosis. However, limitations—including the small pooled-donor sample, the absence of a healthy control group, and a lack of significant GABA modulation—should be considered when interpreting the findings. Although the SHIME^® model is considered a gold standard for microbiota studies, further clinical trials are necessary to confirm these promising results. Full article

Fumonisin B1, deoxynivalenol (DON), and zearalenone (ZEA) are toxic secondary metabolites produced by Fusarium molds. These mycotoxins are common food and feed pollutants and represent a risk to human and animal health. Although the mycotoxins produced by this genus can cross the blood–brain barrier in many species, their effect on neuronal function remains unclear. We investigated the cell viability effects of these toxins on specified neural cell types, including mouse primary neuronal, astroglial, and mixed-cell cultures 24 or 48 h after mycotoxin administration. DON decreased cell viability in a dose-dependent manner, independent of the culture type. Fumonisin B1 was toxic in pure neuronal cultures only at high doses, but toxicity was attenuated in mixed and pure astroglial cultures. ZEA had significant effects on all culture types in 10 nM by increasing cell viability and network activity, as revealed by multi-electrode array measurements. Since ZEA is a mycoestrogen, we analyzed the effects of ZEA on the expression of estrogen receptor isotypes ERα and ERβ and the mitochondrial voltage-dependent anion channel via qRT-PCR. In neuronal and mixed cultures, ZEA administration decreased ERα expression, while in astroglial cultures, it induced the opposite effect. Thus, our results emphasize that Fusarium mycotoxins act in a cell-specific manner. Full article

Although it is more than a century since it was first marketed, acetaminophen remains one of the most popular analgesic agents. In addition, acetaminophen has recently been applied to multimodal analgesia in combination with non-steroidal anti-inflammatory drugs, and its consumption significantly increased during the pandemic of coronavirus disease 2019 as well as diclofenac and ibuprofen. However, the detailed mode of analgesic action of acetaminophen is still unclear. In the present study, we comprehensively discuss conventional, recognized, and postulated mechanisms of analgesic acetaminophen and highlight the current mechanistic concepts while comparing with diclofenac and ibuprofen. Acetaminophen inhibits cyclooxygenase with selectivity for cyclooxygenase-2, which is higher than that of ibuprofen but lower than that of diclofenac. In contrast to diclofenac and ibuprofen, however, anti-inflammatory effects of acetaminophen depend on the extracellular conditions of inflamed tissues. Since the discovery of cyclooxygenase-3 in the canine brain, acetaminophen had been hypothesized to inhibit such a cyclooxygenase-1 variant selectively. However, this hypothesis was abandoned because cyclooxygenase-3 was revealed not to be physiologically and clinically relevant to humans. Recent studies suggest that acetaminophen is deacetylated to 4-aminophenol in the liver and after crossing the blood–brain barrier, it is metabolically converted into N-(4-hydroxyphenyl)arachidonoylamide. This metabolite exhibits bioactivities by targeting transient receptor potential vanilloid 1 channel, cannabinoid receptor 1, Cav3.2 calcium channel, anandamide, and cyclooxygenase, mediating acetaminophen analgesia. These targets may be partly associated with diclofenac and ibuprofen. The perspective of acetaminophen as a prodrug will be crucial for a future strategy to develop analgesics with higher tolerability and activity. Full article

The gut–brain axis (GBA) represents a complex bidirectional communication network that links the gut microbiota (GM) and the central nervous system (CNS). Recent research has revealed that neurosteroids (NSs) play crucial roles in modulating neuroinflammatory responses and promoting neuroprotection. Meanwhile, GM alterations have been associated with various neuroinflammatory and neurodegenerative conditions, such as multiple sclerosis, Alzheimer’s disease, and amyotrophic lateral sclerosis. This review aims to provide a comprehensive overview of the intricate interactions between NS, GM, and neuroinflammation. We discuss how NS and metabolites can influence neuroinflammatory pathways through immune, metabolic, and neuronal mechanisms. Additionally, we explore how GM modulation can impact neurosteroidogenesis, highlighting potential therapeutic strategies that include probiotics, neuroactive metabolites, and targeted interventions. Understanding these interactions may pave the way for innovative treatment approaches for neuroinflammatory and neurodegenerative diseases, promoting a more integrated view of brain health and disease management. Full article

Streptococcus agalactiae (SA) is a severe prevalent pathogen, resulting in high morbidity and mortality in the global tilapia industry. With increasing bacterial resistance to antibiotics, alternative strategies are urgently needed. This study aims to investigate the antibacterial activity and the underlying mechanisms of the natural product xanthohumol (XN) against SA infection in tilapia (Oreochromis niloticus). The results showed that XN could significantly reduce the bacterial loads of SA in different tissues (liver, spleen and brain) after treatment with different tested concentrations of XN (12.5, 25.0 and 50.0 mg/kg). Moreover, XN could improve the survival rate of SA-infected tilapia. 16S rRNA gene sequencing demonstrated that the alpha-diversity index (Chao1 and Shannon_e) was significantly increased in the XN-treated group (MX group) compared to the SA-infected group (CG group) (p < 0.05), and the Simpson diversity index significantly decreased. The Bray–Curtis similarity analysis of non-metric multidimensional scaling (NMDS) and principal coordinate analysis (PCA) showed that there were significant differences in microbial composition among groups. At the phylum level, the relative abundance of the phyla Actinobacteria, Proteobacteria and Bacteroidetes decreased in the MX group compared to the CG group, while the relative abundance of the phyla Fusobacteria, Firmicutes and Verrucomicrobia increased. Differences were also observed at the genus level; the relative abundance of Mycobacterium decreased in the MX group, but the abundance of Cetobacterium and Clostridium_sensu_stricto_1 increased. Metabolomics analysis revealed that XN changed the metabolic profile of the liver and significantly enriched aspartate metabolism, glycine and serine metabolism, phosphatidylcholine biosynthesis, arginine and proline metabolism, glutamate metabolism, urea cycle, purine metabolism, methionine metabolism, betaine metabolism, and carnitine synthesis. Correlation analysis indicated an association between the intestinal microbiota and metabolites. In conclusion, XN may be a potential drug for the prevention and treatment of SA infection in tilapia, and its mechanism of action may be related to the regulation of the intestinal microbiota and liver metabolism. Full article

Background: Finasteride, a 5α-reductase inhibitor commonly prescribed for androgenetic alopecia, has been linked to persistent adverse effects after discontinuation, known as post-finasteride syndrome (PFS). Symptoms include neurological, psychiatric, sexual, and gastrointestinal disturbances. Emerging evidence suggests that PFS may involve disruption of sex steroid homeostasis, neuroactive steroid deficiency (notably allopregnanolone, ALLO), and gut–brain axis alterations. Objective: This study aimed to investigate the effects of finasteride withdrawal (FW) in a rat model and evaluate the potential protective effects of ALLO on gut and hypothalamic inflammation. Methods: Adult male Sprague Dawley rats were treated with finasteride for 20 days, followed by one month of drug withdrawal. A subgroup received ALLO treatment during the withdrawal. Histological, molecular, and biochemical analyses were performed on the colon and hypothalamus. Gut microbiota-derived metabolites and markers of neuroinflammation and blood–brain barrier (BBB) integrity were also assessed. Results: At FW, rats exhibited significant colonic inflammation, including a 4.3-fold increase in Mφ1 levels (p < 0.001), a 2.31-fold decrease in butyrate concentration (p < 0.01), and elevated hypothalamic GFAP and Iba-1 protein expression (+360%, p < 0.01 and +100%, p < 0.01, respectively). ALLO treatment rescued these parameters in both the colon and hypothalamus but only partially restored mucosal and BBB structural integrity, as well as the NF-κB/PPARγ pathway. Conclusions: This preclinical study shows that FW causes inflammation in both the gut and hypothalamus in rats. ALLO treatment helped reduce several of these effects. These results suggest ALLO could have a protective role and have potential as a treatment for PFS patients. Full article

Chirality plays a key role in the effectiveness and toxicity of bioactive compounds. Usnic acid (UA), a lichen metabolite, exists as two enantiomers. Despite numerous studies on its biological properties, enantioselective aspects remain poorly recognized. This study assessed the cytotoxicity of UA enantiomers against colon, prostate, thyroid, brain, and breast cancer cell lines, as well as non-cancerous cells. Cell viability was determined by the MTT assay after 24, 48, and 72 h. Colon cancer HCT116 cells were the most sensitive (IC₅₀ ~10 µg/mL, 72 h), with no enantiomeric dominance. In prostate cancer PC3 cells, (+)-UA was more effective. Moderate cytotoxic effect was noted for thyroid cancer cells; however, this was evaluated for the first time. MDA-MB-231 breast cancer cells were strongly affected (IC₅₀ 15.8 and 20.2 µg/mL for (+)- and (−)-UA, 72 h), as compared to MCF7 cells. Brain cancer cells were the least affected, as so were normal astrocytes. UA had no effect on normal colon epithelial cells but showed moderate toxicity in prostate, thyroid, and breast cells. To conclude, the overall cytotoxicity of (+)-UA was stronger than its (−)-enantiomer, while the latter compound was more toxic to normal cells. These findings highlight the advantage of (+)-UA, especially in chemopreventive strategies. Full article

Background: Oligopeptides from sea cucumber eggs (SCEPs) are rarely studied for their neuroprotective effects. Methods: Therefore, we prepared SCEPs via simulated gastrointestinal digestion and then administered them to an Alzheimer’s disease (AD) mouse model via gavage. Behavior tests, gut–brain histopathology and fecal microbiota transplantation (FMT) experiments were conducted, and gut microbiota and metabolite short-chain fatty acids (SCFAs) were evaluated via 16sRNA gene sequencing and LC-MS. Results: The results showed that both the SCEP and FMT groups experienced improvements in the cognitive impairments of AD and showed reduced levels of Aβ, P-Tau, GFAP, and NFL in the brain, especially in the hippocampus. SCEP remodeled the gut microbiota, increasing the relative abundances of Turicibacter and Lactobacillus by 2.7- and 4.8-fold compared with the model at the genus level. In the SCEP and FMT treatments, four SCFA-producing bacteria obtained from gut microbiota profiling showed consistent trends, indicating that they may be involved in mediating the neuroprotective effects of SCEP. Mechanically, SCEP regulated the SCFA distribution in feces, blood, and the brain, greatly increased the content of SCFAs in the brain up to 2000 μg/mg, eased gut–brain barrier dysfunction, inhibited HDAC3 overexpression, and upregulated BDNF/NT3 levels. Conclusions: This study provides a promising candidate for preventing AD and a reference for applying SCEP. Full article

Background/Objectives: A growing body of evidence is amassing in the literature suggesting a correlation between Alzheimer’s disease (AD) and thrombotic vascular complications, which led to the suggestive hypothesis that thrombosis may contribute to AD onset and progression by damaging the neurovasculature and reducing the cerebral blood flow. In turn, low cerebral blood flow is likely to contribute to neurodegeneration by reducing nutrient and oxygen supply and impairing toxic metabolite removal from the brain tissue. Methods: We searched the literature for studies in animal models of AD or patients diagnosed with the disease that reported circulating markers of platelet hyperactivity or hypercoagulation, or histological evidence of brain vascular thrombosis. Results: Platelet hyperactivity and hypercoagulability have been described in multiple animal models of AD, and histological evidence of neurovascular thrombosis has also been reported. Similarly, clinical studies on patients with AD showed circulating markers of platelet hyperactivity and hypercoagulation, or histological evidence of neurovascular thrombosis collected from post-mortem brain tissue samples. Conclusions: Taken together, a convincing picture is emerging that suggests a strong correlation between systemic or neurovascular thrombosis and AD. Nonetheless, a mechanistic role for haemostasis dysregulation and neurovascular damage in the onset or the progression of AD remains to be proven. Future research should focus on this important question in order to clarify the mechanisms underlying AD and identify a treatment for this disease. Full article

Memory impairment, ranging from mild memory impairment to neurodegenerative diseases such as Alzheimer’s disease, poses an escalating global health challenge that necessitates multi-targeted interventions to prevent progression. Health functional foods (HFFs), which include bioactive dietary compounds that not only provide basic nutrition but also function beyond that to modulate physiological pathways, offer a promising non-pharmacological strategy to preserve memory function. This review presents an integrative framework for the discovery, evaluation, and clinical translation of biomarkers responsive to HFFs in the context of preventing memory impairment. We examine both established clinical biomarkers, such as amyloid-β and tau in the cerebrospinal fluid, neuroimaging indicators, and memory assessments, as well as emerging nutritionally sensitive markers including cytokines, microRNAs, gut microbiota signatures, epigenetic modifications, and neuroactive metabolites. By leveraging systems biology approaches, we explore how network pharmacology, gut–brain axis modulation, and multi-omics integration can help to elucidate the complex interactions between HFF components and memory-related pathways such as neuroinflammation, oxidative stress, synaptic plasticity, and metabolic regulation. The review also addresses the translational pipeline for HFFs, from formulation and standardization to regulatory frameworks and clinical development, with an emphasis on precision nutrition strategies and cross-disciplinary integration. Ultimately, we propose a paradigm shift in memory health interventions, positioning HFFs as scientifically validated compounds for personalized nutrition within a preventative memory function framework. Full article

Medulloblastoma (MB) is the most common malignant brain tumor in children and typically arises in the cerebellum, likely due to disruptions in neuronal precursor development. The primary inhibitory neurotransmitter in the central nervous system (CNS), γ-aminobutyric acid (GABA), exerts its effects through GABA_A, GABA_B, and GABA_C receptors. GABA receptor activity regulates the development and function of cerebellar neurons, including glutamatergic cerebellar granule cells (CGCs). Beyond the nervous system, GABA is also a common metabolite in non-neuronal cell types. An increasing body of evidence indicates that GABA can influence cell proliferation, differentiation, and migration in several types of adult solid tumors, including brain cancers. GABA and GABA_A receptor agonists can impair the viability and survival of MB cells, primarily acting on GABA_A receptors containing the α5 subunit. A marked expression of the gene encoding the α5 subunit is found across all MB tumor molecular subgroups, particularly Group 3 MB, which has a poor prognosis. Importantly, high levels of the γ-aminobutyric acid type A receptor subunit α5 (GABRA5) gene are associated with shorter patient overall survival in Group 3 and Group 4 MB. In contrast, high γ-aminobutyric acid type A receptor subunit β1 (GABRB1) gene expression is related to longer survival in all MB subgroups. The GABAergic system may, therefore, regulate MB cell function and tumor progression and influence patient prognosis, and is worthy of further investigation as a biomarker and therapeutic target in MB. Full article

Background/Objectives: Urolithin A (UA), a gut-derived metabolite of ellagitannins or ellagic acid, has recently gained attention for its potential benefits to brain health. The present research aimed to assess the antidepressant-like properties of UA in both in vitro and in vivo models and explored the molecular mechanisms underlying these effects. Methods: We investigated the antidepressant effects and mechanisms of UA in a model of corticosterone-induced damage to PC12 cells and in a model of chronic socially frustrating stress. Results: Our results demonstrate that UA treatment (5 and 10 μM) significantly alleviated cellular damage and inflammation in corticosterone (CORT)-treated PC12 cells. Furthermore, UA administration (50 and 100 mg/kg) significantly reduced immobility time in the mouse tail suspension test (TST) and forced swim test (FST), indicating its antidepressant-like activity. Additionally, treatment with UA led to the activation of the cAMP response element-binding protein (CREB)/brain-derived neurotrophic factor (BDNF) signaling cascade and triggered the activation of adenosine monophosphate-activated protein kinase (AMPK) during these processes. Importantly, pretreatment with AMPK-specific inhibitor Compound C abolished UA’s cytoprotective effects in PC12 cells, as well as its behavioral efficacy in the FST and TST, and its neurotrophic effects, highlighting the critical role of AMPK activation in mediating these effects. Furthermore, in the chronic social defeat stress (CSDS) mouse model, UA treatment (50 and 100 mg/kg) significantly alleviated depression-like behaviors, including reduced sucrose preference in the sucrose preference test, increased social avoidance behavior in the social interaction test, and anxiety-like behaviors, including diminished exploration, in the elevated plus maze test, suggesting the antidepressant-like and anxiolytic-like activities of UA. Moreover, UA treatment reversed elevated serum stress hormone levels, hippocampal inflammation, and the decreased AMPK/CREB/BDNF signaling pathway in the hippocampus of CSDS mice. Conclusions: Together, these results provide compelling evidence for UA as a viable dietary supplement or therapeutic option for managing depression. Full article

Intermittent fasting (IF) is emerging as a heterogeneous neurometabolic intervention with the possibility of changing the course of neurodegenerative diseases. Through the modulation of the gut–brain axis (GBA), cellular bioenergetics (or metabolic) reprogramming, and involvement in preserved stress adaptation pathways, IF influences a range of physiological mechanisms, including mitobiogenesis, autophagy, circadian rhythm alignment, and neuroinflammation. This review critically synthesises current preclinical and early clinical evidence illustrating IF’s capability to supplement synaptic plasticity and integrity, reduce toxic proteins (proteotoxic) burden, and rehabilitate glial and immune homeostasis across models of Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and amyotrophic lateral sclerosis. The key players behind these effects are bioactive metabolites such as short-chain fatty acids (SCFA) and β-hydroxybutyrate (BHB), and molecular mediators such as brain-derived neurotrophic factor (BDNF). We feature the therapeutic pertinence of IF-induced changes in gut microbiota composition, immune response, and mitochondrial dynamics, and we discuss emerging approaches for merging IF into precision medicine frameworks. Crucial challenges include individual variability, protocol optimisation, safety in cognitively vulnerable populations, and the need for biomarker-guided, ethically grounded clinical trials. Finally, we propose IF as a scalable and flexible intervention that, when personalised and integrated with other modalities, may reframe neurodegeneration from a model of irreversible decline to one of modifiable resilience. Full article